The disclosure relates generally to wireless distribution system (WDS) and more particularly to techniques for distribution of power to antennas within a distributed antenna system (DAS).
Wireless customers are increasingly demanding digital data services, such as streaming video signals. At the same time, some wireless customers use their wireless communications devices in areas that are poorly serviced by conventional cellular networks, such as inside certain buildings or areas where there is little cellular coverage. One response to the intersection of these two concerns has been the use of DASs. DASs include remote units configured to receive and transmit communications signals to client devices within the antenna range of the remote units. DASs can be particularly useful when deployed inside buildings or other indoor environments where the wireless communications devices may not otherwise be able to effectively receive RF signals from a signal source.
In this regard, FIG. 1 illustrates distribution of communication services to remote coverage areas 100(1)-100(N) of a WDS 102 provided in the form of a DAS, wherein ‘N’ is the number of remote coverage areas. These communication services can include cellular services, wireless services, such as radio frequency identification (RFID) tracking, Wireless Fidelity (Wi-Fi), local area network (LAN), wireless LAN (WLAN), wireless solutions (Bluetooth, Wi-Fi Global Positioning System (GPS) signal-based, and others) for location-based services, and combinations thereof, as examples. The remote coverage areas 100(1)-100(N) may be remotely located. In this regard, the remote coverage areas 100(1)-100(N) are created by and centered on remote antenna units (RAUs) 104(1)-104(N) connected to a head-end equipment (HEE) 106 (e.g., a head-end controller, a head-end unit (HEU), or a central unit). The HEE 106 may be communicatively coupled to a signal source 108, for example, a base transceiver station (BTS) or a baseband unit (BBU). In this regard, the HEE 106 receives downlink communications signals 110D from the signal source 108 to be distributed to the RAUs 104(1)-104(N). The RAUs 104(1)-104(N) are configured to receive the downlink communications signals 110D from the HEE 106 over a communications medium 112 to be distributed to the respective remote coverage areas 100(1)-100(N) of the RAUs 104(1)-104(N). In a non-limiting example, the communications medium 112 may be a wired communications medium, a wireless communications medium, or an optical fiber-based communications medium. Each of the RAUs 104(1)-104(N) may include an RF transmitter/receiver and a respective antenna 114(1)-114(N) operably connected to the RF transmitter/receiver to wirelessly distribute the communication services to client devices 116 within the respective remote coverage areas 100(1)-100(N). The RAUs 104(1)-104(N) are also configured to receive uplink communications signals 110U from the client devices 116 in the respective remote coverage areas 100(1)-100(N) to be distributed to the signal source 108. The size of each of the remote coverage areas 100(1)-100(N) is determined by the amount of RF power transmitted by the respective RAUs 104(1)-104(N), receiver sensitivity, antenna gain, and RF environment, as well as by RF transmitter/receiver sensitivity of the client devices 116. The client devices 116 usually have a fixed maximum RF receiver sensitivity, so that the above-mentioned properties of the RAUs 104(1)-104(N) mainly determine the size of the respective remote coverage areas 100(1)-100(N).
Each of the antennas 114(1)-114(N) may be provided as an omnidirectional antenna, which provides equal radiation to 360° around the antenna in the horizontal plan, or as a directional antenna that has radiation energies focused to a certain direction(s). It is also possible to configure each of the antennas 114(1)-114(N) as an antenna array of multiple directional antennas. In this regard, the multiple directional antennas in the antenna array can be arranged to transmit the downlink communications signals 110D in different directions to provide improved RF coverage in the respective remote coverage areas 100(1)-100(N). In this regard, it may be desirable to effectively control directional radiation patterns of the multiple directional antennas to meet specific coverage requirements of the client devices 116 located at certain endpoints in the respective remote coverage areas 100(1)-100(N).
No admission is made that any reference cited herein constitutes prior art. Applicant expressly reserves the right to challenge the accuracy and pertinency of any cited documents.